posdef_swap

(rtools/posdef_swap.m)

Function Synopsis

out = posdef_swap(data,swapdist,irange,jrange)

Help text

function out = posdef_swap(data,swapdist,irange,jrange)

 Due to compression in AirSAR the derived covariance matrix is not necessarily
 positive definite. This causes major problems in the C code for classification
 and segmentation (det is negative, square root gives complex numbers...)
 To avoid this, neighbour swapping is performed with the data up to swapdist away.
 Note that any border at the edges of the data cannot be processed

 Input should be data as a structure .hhhh .hvhv .vvvv .hhhv .hvvv .vvvv
 swapdist is the maximum distance in pixels around problems to swap
 irange,jrange are used to cut out the occasional borders in the range direction or
  simply to cut out a region of interest.

 Source: Mathworld definition of positive definite www.mathworld.com

 Part of the Matlab Radar Toolbox v0.11 by Glen Davidson at www.radarworks.com
 Please acknowledge use of this toolbox in any publication or software.
 This header must be retained in any derivative work

Cross-Reference Information

segmentation_demo             rtools/segmentation_demo.m